Automatic electric heat control.



.I I. G. GEISSINGER. AUTOMATIC ELECTRIC HEAT CONTROL. APPLICATION FILED DEC. 22, 1909.

969,781, C Patented Sept. 13,1910.

' au ucnfor, 1X? fine/so as $61" I @Hozuu To allwhom it may concern;

Be it known that I, HARRY Gr. Gnrssnrcna, a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented new and useful Improvements in Automatic Electrio I-leatControl, of which the following is a specification.

My invention relates to a system for controlling the electric circuits leading to translating devices, andis especially applicable to the control of electric heater circuits.

One of the objects of my invention is to render perfectly safe the control of the electric heaters of public conveyances, such as passenger cars, the staterooms of vessels, or other rooms-in which the public especially are conveyed or housed.

Another object is to provide a system in which a high voltage may be supplied to the heaters and be controlled with facility by means of a delicate thermostat operating in a low voltage circuit.

A further object is to automatically disconnect the heaters from the supply circuit I whenever the doors are left open by accident or otherwise.

' Other advantages will be apparent from 2 may be connected with the axles or metallic frame of the car if a rail or ground return is employed. Thus there would be adifference of potential of six hundred and fifty or more volts between the conductors 1 and 2. The electric heaters 3 are connected directly between the supply conductors and are under the automatic control of the thermostat 4 in the manner hereinafter described;

An operating or regulating circuit 5, con- I nected to the main 2 and to the main 1 through a, switch 7, includes the holding 'or retaining coil 9 of the main circuit-closer whose armature 1-1 cooperates with the conohms,'and that of 15, about 10 ohms, so that the volume of-current in this circuit would be very small, approximately one-third of an ampere. In shunt about the resistance 15 is the circuit containing the door-switch 19 which is normally held in the open position illustrated when the door 20 is closed.

With the values assumed above for purpose of illustration, there would be the very small difference of. potential of about 13 volts at the gap of the thermostatcontacts,

due to the drop across the resistance 15, and

the current would be almost inappreciable, being less than one-tenth of an ampere Thus, the only circuits or contacts which would require to be placed in a position ac- 1 cessible to passengers or the public, are perfectly safe and without depending upon insulation.

The operation of my system of automatic electric heatcontrol may now be explained. When the switch 7 is closed, current will flow through the regulating circuit 5 by way of the armature 22 of the relay and the contact stud 23, which short-circuit the retaining coil 9 of the main circuit-closer, and if the temperature is above normal so that the thermostat contacts are open, neither the relay nor the circuit-closer magnets will be energized. If, however, the temperature is too low, so that the contacts of the thermostat el are closed, energizing the shunt circuit-through the relay coil 18, the armature 22 will be lifted into contact with the stud 24, thus opening the short-circuit about the retaining coil 9 of the main circuit-closer, and diverting the current of the regulating circuit therethrough. With the values previously assumed, if the resistance of this coil is about 80' ohms, there will be but a small diminution of the regulating current and 1 through the resistance26, which may convenientlybe made 500 ohms, and through the lifting coil 10, to the main 2 by way of the heaters 3. The combined magnetic power of the coils 9 and 10, which may be superposed upon the core, raises the armature'll into contact with the stud 12, thus connecting the heaters directly between the supply mains and atthe same time short-circuiting the lifting coil 10, depriving it of its energy but without disconnecting it. The actual flow of current throughthe coillO is, therefore, 'of very brief duration. As above stated, the holding coil 9 has suflicient power to retain the armature 11 in raised position,

and accordingly it will remain in contact with the' stud 12 as long as the relay armature 22 maintains the circuit through the coil 95 The heaters 3, now in operation, warm the air of the car or other compartment until the temperature is raised to the degree at which the thermostat t opens its contacts. When this occurs, the relay coil 18 is denergized, and the armature 22 drops from the contact stud 24, short-circuiting the retaining-coil 9 of the main circuit-closer at the contact 23 and causing its armature ll to .drop from the stud 12, thus cutting out the heaters 3. I

In order that there may not be a useless waste of heat when a door of the car is open, I provide a switch 19 which is normally held in the open position as shown when the door is closed, but which will close a shunt circuit about the resistance 15 when the door is open as shown in dotted lines, thus eliminating the drop of potential across the resistance, denergizing the relay 18 and causing the heater circuit to be' broken in the manner previously described.

It will be observed that a substantially constant current flows through the regulatinghcircuit 5, as long as the system is in operation.

may be used for the operation of other auxiliary apparatus and I have shown,by way of illustration, the lamps 16, though it is evident that other devices may also be inserted.

'VVhile I have only shown one set of heat- .ers 3, it is to be understood that other heaters may be employed and be under the control of the main circuit closer, In case it is desired to short-circuit the thermostatic control apparatus, or to disconnect it from the mains for any purpose, the heaters may be manually connected to the mains by means of a switch 28,.

The advantages to be derived from my invention will be appreciated by those skilled in the art from the foregoing description. It will be observed that I am enabled to vcontrol a high voltage heating circuit by This constant current circuit ing 'devlce arranged to'connect said heater to supply malns having an armature connected circuit closer for the heaters also carries an Iposeof illustrating one embodiment of my invention, and it is to be understood that departing from the spirit of my invention, since What I claim and desire to secure by Let ters. Patent, is i 5 1. A system of automaticheat control, comprising an electric heater, and a circuit closing device arranged to connect said heater to supply mains having an armature connected with the closer contacts and energizing coils comprising lifting and retaining coils cooperating to raise the armature, said lifting coil being shortcircui t ed by said armature when in raised position.

2. A- system of automatic heat control,

comprising an electric heater, a circuit closmany changes can be made therein without ing device arranged to connect said heater to supply mains having an armature connected with the closer contacts and energizing coils comprising lifting and retaining coils cooperatingto raise the armature, said lifting coil being short-circuited by said armature when in raised position, and a regulating circuit for said circuit closing device having mechanism for short-circiuting said retaining coil.

3. A system of automatic heat control, comprising an electr c heater, acircuit closcomprising an electric heater, a circuit closing device arrangedtoconnect said heater to supply mains having an armature connected vith the closer contacts and energizving coils comprising lifting and retaining coils cooperating toraise the armature, said llft-ing coil being short-circultcd by said armature when m raised position, a regulating circuit for said circuit closing device having mechanism for short-circuiting said retain- 2'5 Y of said coils.

ing coil, a thermostat controlling'the open ation of said mechanism, and a switch for nullifying the controlling eiiect of the thermostat; i J

.5. A system of automatic heat control, comprising an electric heater and a circuit closing device connecting the heater to supposition.- J

ply mains, said device having an armature controlling main contacts and energizing coils for actuating the armature connected .respectively in shunt and in series with the heater,vand one of saidcoils being short-circuited when the armature is -in attracted 6. A system of automatic heat control,

- comprising an electric heater, a circuit closing device connectingtheheater to supply mains, said device having an armature-controHing'main' contacts and energizingcoils for actuating the armature connected respectively in shunt and in series with the heater, and one of said coils being short-cir cuited when the armature is in attracted position, and a thermostat having connections for controlling a short-circuit about the other .7. A. .system" of automatic "heat control, comprising an electric heater,- a' circuit closing device connecting the heater to supply mains, said device having an armature controlling main contacts and energizing coils for actuating the armature connected respectively in shunt. andin seriesvwith the heater, and one of-said coils being short-circuited' when the armature is in attracted position, electromagnetic mechanism arranged to short-circuit said other coil, and a thermostat connected with and' controlling said mechanism.

8. A system of automatic heat control,

comprising. an electric'heater, a circuit 6105- ing device connecting the heater to supply. mains, said device having an armature controlling main contacts and'energiz ing coils' for actuating the armature connected re-f spectivelyin' shunt and in series with the heater, and one of said coils being shortcircuitedwhen the armature-is in attracted position, electromagnetic mechanism arranged to short-circuit said other coil, a thermostat connected with and controlling said mechanism, and a device for nullifying the controlling efiect' of said thermostat.

9. system of automatic heat control, compr singtan electric'heater, a circuit clos-v -'-,ing device having contact to connect the heater with supply mains, said device having an armature to'cont-rol said contacts and energizing coils comprising lifting and retaining coils cooperating-to lift the armature, a regulating circuit in shunt 'to said heater and having said retaining coiland a resistance included therein, a device for short circultingthe retaining coil, and a thermostat in shun'tto said resistance and controlling the operation of said short-circuiting device.

10. A system of automatic heat control, comprising .an electric heater, a circuit closing devicehaving contacts to connect the heater with supply mains, said device having an armature to control said contacts and which said energizing coil. is connected and which'normally carries a substantially constant current and means-for connecting and disconnecting said circuit to the supply mains.

12. A system of automatic heat control, comprising an electric heater, acircuit-closing device arranged to connect said heater to, supply mains, said device'having an armatwo operating to control the contacts of sald clrcult-clos'ing device and energizing,

coils comprising lifting and retaining coils cooperating to raise said armature, a constant-current regulating circuit to which said retaining coil is connected, a switch for short-circuiting said retaining coil and a thermostatically controlled 'clrcuit having therein a relay magnet to actuate said switch. v I

13. A system of automatic heat control; com rising an electric heater, a circuit-closing evice arranged to connect said heater to supply mains, said'device having an armature operating to'control the contacts of said circuit-closin device and ener iziiw coils g l e a com risin liftin and retainin coils cooperating toraise said armature, a regulating clrcult, a switch member connected to said circuit which in one position shortclrcuits said retaining coil and 1n another positionconnectsone terminal of the lifting coil tothe regulating circuit, a'shunt to a portion of said regulating circuit including a thermostat and a relay coil toactuate said switch-member.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses HARRY G. GEiss N-GER.

Witnesses:

LAURA SMITH, LOUISA E. Snuson. 

